Generally, a head lamp of a vehicle, also called a head light, lights a front view for safe driving of the vehicle at night or in a dark area.
The head lamp produces a light beam which can be shifted in up/down directions to not dazzle a driver of an oncoming vehicle from an opposite direction. According to safety standards, the high beam is required to identify an obstacle existing at 100 m ahead of the vehicle, and a low beam is required to identify an obstacle at 40 m ahead of the vehicle.
In order to implement such light beam, a shield is disposed between a light source and a lens. The shield shields a portion of a light incident on the lens from the light source or a reflective mirror. According to a shape and movement of the shield, the high beam or the low beam can be selectively implemented.
Because the light shielded by the shield is not used to illuminate, the efficiency of head lamp is limited. In addition, if luminance efficiency of the light passing through the shield is low, the head lamp efficiency may deteriorate in comparison to that of the light source. Thereby further the head lamp efficiency. Particularly, when the low beam is used, the amount of the effective light emitted from the head lamp may be deteriorated as the amount of the light shielded by the shield is increased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.